Ferritin (Iron Storage Protein)
Ferritin is the protein that stores iron inside cells and slowly releases it when the body needs it. A serum ferritin blood test measures how much iron is stored in your body. Importantly, ferritin depletes before haemoglobin does — so ferritin is the earliest indicator of iron deficiency, even when your haemoglobin and blood count appear normal.
Normal Range
Men: 20–300 ng/mL; Women: 12–150 ng/mL; Children: 7–140 ng/mL
Reference ranges may vary slightly between laboratories. Always interpret your result in context with your doctor.
Why is Ferritin measured?
Ferritin is tested to diagnose iron deficiency (the most common nutritional deficiency worldwide), investigate unexplained fatigue, hair loss, restless legs, or poor exercise performance, and to monitor iron status in pregnancy, regular blood donors, or those with chronic disease.
High Ferritin means…
Elevated ferritin above 300 ng/mL in men or 150 ng/mL in women can indicate iron overload (haemochromatosis), liver disease, inflammatory conditions, or infection (ferritin is an acute-phase protein that rises with inflammation). It needs to be interpreted alongside transferrin saturation and CRP.
Low Ferritin means…
Low ferritin (below 12 ng/mL) confirms iron deficiency. Even 'low normal' ferritin (below 30 ng/mL) causes symptoms in many people — particularly fatigue, brain fog, hair shedding, and reduced exercise tolerance — even when haemoglobin is still normal.
Symptoms associated with abnormal Ferritin
When Ferritin is high:
- Usually asymptomatic unless iron overload
- Joint pain and fatigue (haemochromatosis)
- Bronze skin discolouration (advanced haemochromatosis)
When Ferritin is low:
- Persistent fatigue out of proportion to activity level
- Diffuse hair shedding (telogen effluvium)
- Restless legs syndrome
- Brittle nails or spoon-shaped nails (koilonychia)
- Difficulty concentrating (brain fog)
- Reduced athletic performance
How to improve your Ferritin
- Red meat, organ meats (liver), and shellfish (oysters, clams) are the richest sources of haem iron, which is absorbed 2–3× more efficiently than plant iron.
- For plant-based diets, combine iron-rich foods (lentils, tofu, spinach, pumpkin seeds) with vitamin C to maximise absorption.
- Ferritin below 30 ng/mL may benefit from supplementation even if haemoglobin is normal — discuss with your doctor.
- If your ferritin is high, avoid iron supplements and vitamin C supplements until you understand the cause.
Frequently asked questions about Ferritin
Can low ferritin cause hair loss?
Yes — low ferritin is one of the most common and under-recognised causes of female hair loss. The hair follicle uses iron for rapid cell division. Studies show women with diffuse hair shedding consistently have lower ferritin levels than those without. Many experts recommend ferritin above 50–70 ng/mL to support hair growth.
What is the difference between ferritin and haemoglobin?
Haemoglobin is the oxygen-carrying protein in red blood cells — a low haemoglobin means anaemia. Ferritin is the iron storage protein. You can have low ferritin (depleted iron stores) with a normal haemoglobin — this is called iron deficiency without anaemia, and still causes significant symptoms.
Medical Sources
- ↗ NIH Office of Dietary Supplements — Iron Fact Sheet
- ↗ British Society of Haematology — Guidelines on Iron Deficiency
This page is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare provider about your individual results.